Adjustable carbon monoxide alarm



p 1941- I J. J. GUARAGNA 2,254,480

ADJUSTABLE CARBON MONOXIDE ALARM Filed March 9, 1939 3 Sheets-Sheet l WITNESS Sept. 2, 1941. .1. J. GUARAGNA 2,254,430

ADJUSTABLE CARBON MONOXIDE ALARM I Filed March 9, 1959 3 Sheets-Sheet 2 lo INVENTOR- Jogeph c7. Guarac WITNESS Sept 2, 1941. J. J. GUARAGNA ADJUSTABLE CARBON MONOXIDE ALARM Filed March 9, 1939 3 Sheets-Sheet I5 Joseph JG uarac nd INVENTOR 5 5 E N W W Patented seat. 2, 194? f UNITED ,ISTATESIIPATENT: OFFICE ADJUSTABLE cnniir iri vzonoxma Joseph J. Guaragna, South Boston, Mass. Application March 9, 1939, Serial naizeosza 2 Claims.-

The invention relates to a combined detector and indicator device, designed primarily for use for detecting and indicating to a person, within an enclosed space the presence of carbon monoxide gas, but it is to be understood'that the device, in accordance with this invention is for use in any connection for which it' maybe found I applicable.

A further object of the invention is the provivision of a device for the purpose set forth and in a manner wherein its construction is novel in its entirety andis capable of being placed within an enclosure, such as a garage, room, automobile of the closed body type or in any other places where poisonous gases could accumulate and become effective for jeopardizing life both in human beings and animals.

Further objects of the invention are to provide, in a manner as hereinafter set forth a device for the purpose referred to which is simple in its construction and arrangement, strong, durable, compact, readily assembled, thoroughly efficient in its use and comparatively inexpensive to set up.

With the foregoing and other objects in view,

- the invention consists of a novel construction,

combination and arrangement of parts as will be more specifically described and illustrated in r flcations may be resorted to which fall within the scope of the invention as claimed.

In the accompanying drawings wherein like reference characters denote corresponding partsv throughout the several views:

Figure 1 is a front elevation of a combined detector and indicator device in accordance with this invention.

Figure 2 is a vertical sectional view thereof.

" Figure3 is a vertical sectional view of the de- 5. vice. g

' The device includes a housing i mounted on a hollow base 2. Suspended from the bottom 3 of housing I and arranged within the base 2 is a receptacle. 4 formed from closely woven reticulated material possessing heat resisting characteristics. The receptacle 4 preferably is open atits top, but if desired it may be closed by a screen-like cover. The receptacle 4 at its top is provided with laterally extending flanges 5, and it is detachably connected or suspended from the said bottom 3 by the means 6, which coacts with the flanges 5. Arranged within the receptacle 4 is a pair of foraminous spaced parallel partitions I which divide receptacle 4 into the compartments 8, 9 and air circulates through all sides of the said compartments. The compartment 9 is filled with the' catalyst Hopcalite, while the compartment 8 is filled with an inert substance such as sand. Arranged within the receptacle 4 are thermocouples iii. A circuit conductor ll extends from a terminal of the thermocouples, passes through the bottom 3 of housing I into the latter. The conductor II will be further referred to. The number of thermocouples ill may 0 be as desired, but the number will be such, so that, about a millionth part of carbon monoxide per volume will actuate a relayJZ in any atmospheric temperature, due, of course to the automatic adjustment of a sensitivity switch, to be referred to by variations of temperature.

The relay i2 is arranged within the upper portion of housing I. The device also includes a milliameter I3 which is positioned in the lower portion of housing i below the sensitivity switch I and visible from the front of the housing. The switch I4 is arranged within a protective casing i5 which is suspended from the housing and connected as at It to the housing front wall. The front wall ll of easing i5 has its lower portion formed. of a horizontally disposed segmental shaped slot l8 having its top edge notched as at IS. The upper portion of thewall ll, of the casing i5 is formed throughout with spaced relatively large openings '20 which are screened as at 2|. The'top, bottom, side and end walls of casing l5 may be formed with screened openings in the same manner as the upper portion of casing wall l1.

The switch as shown includes spaced concen-. 5 tric rows of spaced contacts 22. The contacts 22 of the inner 'row are staggered with respect to the contacts 22 of the outer row. The number of contacts 22 will be as desired, but each contact 22 will be electrically connected to a thermocouples lfl, at the right of the latter by a circuit connection or wire 23. Preferably the number of contacts 22 will be fifty-one, to correspond from zero to onehundred degrees F. Every contact piece of theswitch l4 will have a difference of two degrees F., therefore associated as zero to one hundred degrees F., fifty-one contacts are required. It will be pointed out that each of the conductors 23 from the contacts, will be connected to the thermocouples so that, according to whatever number of thermocouples required, the conductors 23 will be distributed and connected to the thermocouples so that about one millionth part per volume of carbon monoxide will ac- Y tuate relay l2 regardless ofwhich contact 22 the needle or circuit closer 24 of the switch may rest on. thus making'a uniform reaction with. the

same concentration of carbon monoxide zero F., to one hundred degrees F.

The switch l4 includes an actuating means for the needle or circuit closer 24 and the said means includes a thermostatic controlled elefrom ment 25 and a rotatably mounted insulated shaft 1 26. The element 25 is in the form of a coiled thermostatically controlled metallic strip connected at its inner end to the shaft 26. The

outer end of element 25 is fixed to an adjustable support 21. The inner end of the needle or circuit closer 24 isflxed to the shaft 26. The needle l8 which, when atmospheric temperature is zero F., it will rest in the position as shown on left.

at the extreme left as shown; and with every p two degrees F. rise at normal temperature, the

needle will move on to another contact, thus severing more thermocouples of each contact.

The contacts will be so arranged that the needle will always be in contact. If normal temperature is high and later becomes lower the needle 24 will move toward the left, so that each contact it touches will put into effect a number of thermocouples according to the demand placed-upon it by the variations of temperature, thus making it uniform regardless of temperature variations and assuring a reaction, when carbon monoxide is in the air as quickly at zero F. as at one hundred degrees F.

Both outer extremesof the outer contacts 22 of the outer row of contacts of switch l4 are the alarm and will indicate to a person that a provided with stops 28 to prevent the passingoif switch 38 and extending from the .latter to a contact of the relay I2 is a circuit conductor 3|. From the conductor 28 leads a circuit conductor 32 to a terminal of the milliameter l3. The needle or indicator 34 of the milliameter has its inner end attached to a carrier or centerpiece 35, and to the latter is secured an angle-shaped extension piece 36 connected with a circuit conductor 31' leading from the relay l2. To the lowest temperatures.

right of and associated with the extension 36 is a metallic curved contact piece 38 connected at one end to anextension 38 of the conductor 32. Leading from a terminal of the milliameter 3 to the relay I2 is a circuit conductor 33.

A signal which may be of the visible or the audible type forms an element of the device and is shown by way of example in the form of an alarm, as indicated at 48 and which preferably will be supported at the top of housing I. Leading from the alarm 48 are circuit conductors 4|,

42. The conductor 4| is connected to the main 7 switch 43 of the device. The conductor 42 is connected to the relay l2 and leading from the latter to the switch 43 is a circuit conductor 44. Enclosed withthe switch 43 is a transformer 45 to which is attached a coupling cord 48 provided with aconnection plug 41 for connecting the device to a source of electrical supply. The I There will be fifty-one contacts arranged asshown, so that the needle will always be in con- -tact. More or-less contacts and thermocouples may-be used as desired for quicker reaction at high and later becomes lower the needle will be moving toward the left, so that the contact it touches will put into effect a number of thermocouples, etc., according to the demand put 'upon it by the variations of temperatures thus making it uniform regardless of temperature variations and assuring a reaction when ca'rbon monoxide is in the air as quickly at zero F., as at one hundred degrees-F.

The extension and contact 38 provide when in coacting relation what may be termed the effecting of an extra contact or circuit closing independently of the conductors 28, 3|. The contact piece 38 is placed at such a position that when the needle of the milliameter approximates a given number, the point of dangerous concentration, theextension 36 will engage with the contact 38 thereby closing the signalling circuit and providing an alarm. This what is termed an extra contact or adjustment is suitable for garages or other places where there is always a certain amount of monoxide gas in the air so that the thermostatic switch 38 may be turned off, but owing to the coaction of the extension 36 and contact 38 it provides for the sounding of dangerous concentration is in the air. For places where no carbon monoxide is inevidence, by .way of ,example, homes, ofllces, etc., the switch 38 will be kept on "on position."

The support 21, as it is adjustable may adjust the sensitivity of the element 25, so the latter will have its full eifect. As element 28 is set from right to left, it becomes less sensitive.

It is readily obvious that regardless of normal temperature variations, about the same concentration of carbon monoxide will effect the milliameter needle to move to a given number, so

- that, a danger point line may be drawn on the milliameter and the extra contact due to the coaction of extension 36 and contact 38 is placed at a point approximating this line, so that, at any temperature when a dangerous concentration If normal temperature is of carbon monoxide is in the a this extra contact will provide always for giv g an alarm.

The switch 30, which, when the device is used in places where no evidence of carbon monoxide is in the air, the switch will always be kept on, but if used in any places, as explained previously, where a certain amount of carbon monoxide is constantly in the air, the switch 30 will be turned off and the coaction oi the extension 36 and will be efiected to close the alarm circuit when the milliameterneedle has approximated the danger line. r

, It is readily apparent that when the carbon monoxide gas contacts the receptacle 4, heat is evolved through the coaction or the gas with Hopcalite. The hat evolved will produce av current corresponding to the concentration of carbon monoxide in the atmosphere in the thermocouples. There will be enough thermocouples so that one millionth part per volume of carbon.

monoxide at any temperature will actuate the relay I2 at ten milliamperes thus sounding an alarm and afiecting other devices or. objects which :may be connected to it.

As set forth the switch It is of the thermostatic coil controlled type. The switch M will operate on the same principle as a thermostatic 'coil dial room thermometer, excepting that in this instance the dial is replaced by a very light weight needle of "any suitable light metallic material, this'needle is the circuit closer 24 which instead of reading the room temperatu're it will i be in constant engagement with contacts 22 of the switch it, moving one way or the other, according to the atmospheric temperature, thus either severing or adding more-thermocouples and giving a uniform reaction of monoxide with the catalyst regardless of the atmospheric temperature. The circuit closer will rotate on a very thin central axis, thus assuring smooth rests on (according to room temperature at that moment) will have enough thermocouples connected to it to actuate the relay at about one millionth part of carbon monoxide per volume of air; this will compensate for the variations of temperature.

Nothing will affect the thermocouples except when monoxide gas in the air contacts the chamber with the catalyst; that is why the catalyst is in one chamber with the ends of the thermocouples, and an inert substance is in the other chamber with the other ends of the thermocouples, thus making both sides equal in normal conditions.

When j monoxide permeates the atmosphere, it will then react with the catalyst, producing more or "less-heat in, the chamber containing the catalyst, and the ends of the thermocouples.

At all times, the only reaction is in the chamber which contains the catalyst, thereby generating and a sensitivity switch associated with the thermocouples for compensating the change from high and low sensitivity of the generator by an opposite change in the number of thermocouple connections therewith. I

2. A combined detector and indicator device for the purpose set forth, comprising an electric circuit, a thermoelectric generator for energizing therewith, and means for adjusting said switch;-

. JOSEPH JLGUARAGNA. 

